Spring core

ABSTRACT

A spring core includes a plurality of rows of springs which are disposed parallel to each other and each of which includes a plurality of individual springs connected to each other. The spring core is designed in such a way that each spring is in the form of a ring which is disposed on edge in the loading direction and made of an elastically deformable wire having an inwardly directed notch in the progression of the contour.

The invention relates to a spring core according to the preamble of claim 1.

Spring cores are used in different areas. Spring cores for upholstered furniture, and especially mattresses, can be mentioned in this case by way of example.

In this case, the individual springs are made of wire, which is usually a metal wire which is wound in a helical manner.

In the case of so-called Bonnell spring cores, several springs are joined into a row and are connected to each other by helically wound wires which engage in end rings of the individual springs.

In order to obtain desired zonings which differ with respect to their springiness behaviour, a number of measures are known from the prior art. These include a respective configuration of coatings that cover the spring core for example, especially such of a textile nature, but also the type of material of the springs, their shape and dimensioning, as well as the external dimensions and the wire thickness, by means of which different spring characteristics are achieved.

All these measures show considerable disadvantages with respect to the production of such a spring core or a complete innerspring mattress, and/or with respect to the utilisation thereof.

The production of such spring cores with different zonings is especially complex for a series product and is thus accordingly expensive.

This also includes the separate production of the different springs which are respectively provided for the zoning.

The invention is based on the object of further developing a spring core of the generic type in such a way that it can be produced in a simpler way and at lower cost, and different spring characteristics can be set without any problems.

This object is achieved by a spring core with the features of claim 1.

Such a spring core can be varied with respect to its springiness behaviour as required without changing the spatial shape of the individual springs, wherein it is not only possible to substantially produce without any additional effort a spring core that differs from another one, but also such spring cores with partially different springiness behaviour.

The initial product is formed by quasi-identical individual springs, in which only a single twisting of the individual springs is carried out, preferably of a row comprised of several springs, in order to enable setting the different springiness behaviour. This leads to a change in the characteristics, because the shaped notch then assumes a respectively different position.

Said notch is formed by two legs which enclose an angle 90°. The tip of the notch preferably protrudes beyond the centre of the formed ring. The length of the lever arm which is formed by the legs changes as a function of the rotation of the springs and thus the effective momentum under load, and the spring characteristics change accordingly.

For the purpose of forming a row of springs, several springs that are arranged in parallel and spaced from each other are preferably connected to each other by two connecting elements, which occurs in such a way that precise positioning with respect to each other is permanently ensured.

For this purpose, the connecting elements, which are especially provided in form of rods, can be fixed to the springs in an interlocking manner. A materially bonded connection such as gluing, welding or soldering can principally also be considered. Such a connection is less suitable for a series product however because it can only be produced with a relatively high amount of effort.

The springs of one row can be situated congruent with respect to each other, i.e. the notches of all springs are in alignment, so that by twisting the row the spring characteristics are changed in their entirety. A zoning can thus be achieved which remains constant over the entire extension of the row, wherein said extension usually determines the width of the spring core.

As already mentioned above, other rows are twisted for changing the spring characteristics. All rows are fixed at the end side to a frame which encases the spring core, wherein the aforementioned rods can be used for this purpose.

In addition to the aforementioned zoning of the spring core in rows by twisting a complete row, it is also possible to twist individual springs of a row or a group of springs of a row in relation to the springs of another row, so that sections of the spring core can be configured as desired in different ways with respect to the springiness behaviour.

A cost benefit that is obtained with respect to the prior art is that the same springs can be used for all requirements.

It can also principally be considered to additionally change the springiness behaviour of the individual springs in such a way that, as up until now, different wire thicknesses are used, even though the advantage as described above is not provided to such an extent.

Further advantageous embodiments of the invention are described in the dependent claims.

An embodiment of a spring core in accordance with the invention will be described below by reference to the enclosed drawings, wherein:

FIG. 1 shows a spring core in accordance with the invention in a perspective view;

FIG. 2 shows a part of the spring core which is also shown in a perspective view;

FIG. 3 shows an enlarged section of the illustration according to FIG. 2;

FIGS. 4a ) to 4 c) shows springs of the new spring core, but in different positions in a schematic view.

FIG. 1 shows a spring core, comprising a plurality of rows 1 of springs which are arranged in parallel with respect to each other and of which each includes several individual springs 3 which are connected to each other, wherein the rows 1 of springs are respectively retained at the top and bottom on a circumferential frame 2.

Each spring 3 is formed as a ring which is arranged on edge in the direction of loading and is made of an elastically deformable wire, having an inwardly directed notch 4 in the progression of the contour.

As is shown especially clearly in FIGS. 2 and 3, the springs 3 of a row 1 of springs, which are arranged in parallel and spaced from each other, are connected to each other by a rod 5, which preferably also is made of wire, wherein the wire of spring 3 is surrounded in the manner of a knot 6.

In order to prevent that the rod 5 protrudes beyond the outer edge of the spring 3 and thus impairs the reclining property of the spring core, each knot 6 is arranged in an indentation of the spring 3, so that the rod 5 rests therein in a sunk manner. Apart from that, rods 5 are provided on two opposite sides, so that the row 1 of springs produces a stable structure.

In FIGS. 4a ) to 4 c), the springs 3 are shown in different twisted positions, with a respectively different positioning of the notch 4. The spring characteristics of the spring 3 change depending on the position of the spring 3 or the notch 4.

The notch 4 is formed by two legs 7 which are positioned at an acute angle with respect to each other and whose apex is situated outside of the central point of the spring 3 shaped in the manner of a circular arc, and goes beyond said central point.

In the position shown in FIG. 4a ), the legs 7 have the greatest length acting as a lever with respect to the load recognisable by arrow B, which thus produces the greatest effective momentum.

A respectively large spring deflection is thus achieved, i.e. the spring is characterized by its softness in a manner of speaking, in which it substantially deforms in the direction of loading.

In contrast, FIGS. 4b ) and 4 c) show springs 3 twisted about the imaginary central axis, with the resulting positions of the notches 4 and, relating to the loading B, a smaller acting lever by the position of the legs 7, wherein FIG. 4c ) represents the position in which the springs 3 shows the greatest hardness.

The springs 3 are arranged otherwise in such a way that they engage in the formed intermediate spaces between the individual springs 3 of the adjacent spring rows 1, so that a relatively closed support surface is produced. 

1.-10. (canceled)
 11. A spring core, comprising a plurality of springs disposed to define rows of springs in parallel relationship, with the springs of each of the rows being connected to each other, each spring being formed as a ring which is disposed on edge in a loading direction and made of elastically deformable wire having an inwardly directed notch in a progression of a contour.
 12. The spring core of claim 11, wherein the contour of the spring is formed as a circular ring section, said notch adjoining the circular ring section.
 13. The spring core of claim 11, wherein the notch is limited by legs which enclose an angle of ≦90°.
 14. The spring core of claim 12, wherein the notch defines an apex which is disposed in a region of an imaginary central point of the circular ring section or outside thereof.
 15. The spring core of claim 12, wherein the notch defines an apex which is disposed in a region beyond an imaginary central point of the circular ring section.
 16. The spring core of claim 11, wherein the springs in one of the rows of springs are twisted relative to the springs of another one of the rows of springs with respect to a position of the notches.
 17. The spring core of claim 11, wherein the springs of one of the rows of springs are twisted in relation to other springs of said one of the rows of springs.
 18. The spring core of claim 11, further comprising at least two rods configured to connect the springs of one of the rows to each other, said at least two rods being locked with respect to each other at a distance.
 19. The spring core of claim 18, wherein the springs of the one of the rows of springs are connected by the at least two rods in a connecting region which is arranged in an indentation of the springs.
 20. The spring core of claim 11, wherein the springs of one of the rows of springs engage in intermediate spaces of the springs of at least one adjoining one of the rows of springs.
 21. The spring core of claim 11, wherein the springs of one of the rows of springs have a wire thickness which is different from a wire thickness of the springs of another one of the rows of springs. 